1. Field of the Invention
The present invention relates to the recrystallizing of polycrystalline or amorphous or small grain material to produce as large a grain size as possible, and more particularly is directed to improvements in growing a single crystal film by recrystallizing a polycrystalline or amorphous upper layer extending over an electrically isolating layer on a single crystal semiconductor substrate.
2. Description of the Prior Art
In growing a single crystal film from a polycrystalline or amorphous layer extending over an electrically isolating layer on a single crystal substrate, energy sources which emit beams of charged particles, such as, a spot electron beam or electron strip beam, can be used to scan and thereby melt the polycrystalline layer so as to induce liquid or solid phase regrowth by epitaxial recrystallization.
However, as the beam scans the polycrystalline or amorphous layer, some of the charged particles are able to travel therethrough and are absorbed by the electrically isolating layer on the substrate. In particular, a layer of charged particles is formed on that portion of the electrically isolating layer bordering the polycrystalline or amorphous layer. As a consequence thereof, as the beam subsequently scans the polycrystalline or amorphous layer, the layer of charged particles deflects the beam so that the latter cannot be adequately focused on the polycrystalline or amorphous layer for sufficiently melting the same.